镉和铅对鲫鱼肝胰脏过氧化氢酶活性的影响

The Effect of Cadmium and Plumbum on Activities of Catalase from Hepatopancreas of Carassius auratus

采用急性毒性实验方法,研究了不同ρCd2+和ρPb2+及二者混合溶液,染毒24、48、72、96 h后,对鲫鱼肝胰脏过氧化氢酶(CAT)活性的影响.结果表明:在实验剂量范围(ρCd2+为0.5～6.0 mg/L,ρPb2+为10.0～40.0 mg/L),0.5、2.0 mg/L的Cd2+对CAT活性有诱导作用,6.0 mg/L的Cd2+对CAT活性有抑制作用;Pb2+胁迫对CAT活性随着染毒时间的延长而逐渐降低;2.0 mg/L Cd2+与20.0 mg/L Pb2+混合胁迫对CAT活性有明显的诱导作用;0.5mg/L Cd2++10.0 mg/L Pb2+,6.0 mg/L Cd2++40.0 mg/L Pb2+混合胁迫对CAT活性有明显抑制作用.Cd2+和Pb2+胁迫对CAT活性的影响呈剂量效应,二者关系曲线为抛物线,抛物线顶点是鲫鱼对Cd2+和Pb2+污染从适应到中毒反应的阈值,可间接作为检测环境污染情况的指标.

The influence of cadmium（Cd2＋）,Plumbum（Pb2＋） to the activity of catalase（CAT） from the hep-atopancreas of Carassius auratus was investigated by using acute toxicity test for 24,48,72 or 96 h in the pres-ence of different concentrations of either or both of these two metal ions.The results showed that in the experi-mental dose range（the concentration of Cd2＋ ranging from 0.5 ~ 6.0 mg/L and which of Pb2＋ ranging from 10.0 ~ 40.0 mg/L）,the activity of CAT was enhanced in the presence of 0.5 ~2.0 mg/L of Cd2＋,while which was inhib-ited by 6.0 mg/L of Cd2＋.The inhibition ability of the activity of CAT by Pb2＋ declined with the exposure time in-creasing.The activity was significantly raised up by the mixture of both 2.0 mg/L Cd2＋ and 20 mg/L Pb2＋,and dropped down in the presence of the mixture of 0.5 mg/L Cd2＋ and 10 mg/L Pb2＋,or the mixture of 6.0 mg/L Cd2＋ and 40 mg/L Pb2＋.It also revealed the dose-effect relationship between the activity of CAT and these two metal ions,which is a parabola curve and the vertex indicates the toxication threshold of the hepatopancreas of Caras-ius auratus,which may be used as an indirect indicator for the environmental pollution.